cAMP Biosensor Assay Using BacMam Expression System: Studying the Downstream Signaling of LH/hCG Receptor Activation

Cyclic adenosine monophosphate (cAMP) serves as a second messenger for numerous G-protein-coupled receptors. Changes in cellular cAMP levels reflect the biological activity of various GPCR-specific agents, including protein hormones. cAMP biosensors based on detection of Förster-type resonance energy transfer (FRET) offer unique advantages including the ratiometric nature of measurement, adjustable affinity toward detected molecule, capability of monitoring kinetics of cAMP release, and compatibility with the multi-well format and fluorescence plate reader platforms. In this chapter, we introduce the optimized version of the previously reported method to achieve sufficient and reproducible level of cAMP biosensor protein expression with the means of BacMam transduction system. As a practical challenge, we address the applicability of the designed assay for screening of biological activity of human hormones, including human chorionic gonadotropin (hCG) bearing different posttranslational modifications.

Luteotropic effects of human chorionic gonadotropin administered 7.5 days after synchronous estrous induction in Morada Nova ewes

This study was conducted in ewes to assess effects of human chorionic gonadotropin (hCG) administration after imposing an estrous induction treatment regimen. Ewes (n = 115) were treated with a 60 mg medroxyprogesterone-intravaginal-sponge for 6 d plus 200 IU of equine chorionic gonadotropin (eCG) im and 37.5 μg d-cloprostenol im 36 h before sponge removal (Day 0). After natural mating, ewes having at least one corpus luteum (CL; n = 108) were administered either 1 mL of saline (G-Control; n = 53) or 300 IU of hCG (G-hCG; n = 55) on Day 7.5 after sponge removal (Day 0). Ovarian ultrasonography and blood collection were performed on Days 7.5, 13.5, 17.5, 21.5, and 30.5. Accessory CL (aCL) were observed in 81.5 % (G-hCG) and 0.0 % (G-Control) of ewes (P = 0.0001). Diameter, area, and volume of luteal tissue were greater (P < 0.05) in G-hCG from Day 13.5 to 30.5. Progesterone (P4) concentrations were greater (P < 0.05) on Days 13.5, 17.5, 21.5 and 30.5 for ewes of the G-hCG group. Pregnancy percentage was similar (P = 0.25) between groups [47.1 % (G-control) compared with 60.0 % (G-hCG)], although total number of lambs produced by estrous synchronized ewes was greater (P = 0.005) in ewes of the G-hCG group (90.9 % compared with 66.0 %). In conclusion, hCG administration 7.5 days after sponge removal from Morada Nova ewes during the non-breeding season is an effective treatment to induce aCL formation, improve luteal tissue biometry and P4 concentrations, and to enhance the total number of lambs born.

Effect of HCG-Triggered Ovulation on Pregnancy Outcomes in Intrauterine Insemination: An Analysis of 5,610 First IUI Natural Cycles With Donor Sperm in China

Objective: To evaluate the effect of human chorionic gonadotropin (hCG) trigger ovulation on pregnancy outcomes in natural IUI cycles with donor sperm. Methods: This retrospective cohort study included 5,610 first-natural IUI cycles with donor sperm in infertile couples during the period from January 2012 to December 2017. To control for other confounding factors, our analysis was restricted to normo-ovulatory women without tubal infertility. The main outcome measure was live birth rate; the secondary outcomes included rates of clinical pregnancy and miscarriage. Results: In the crude analysis, both the clinical pregnancy (27.40 vs. 22.73%; P = 0.001) and live birth rates (24.52 vs. 20.13%; P = 0.007) were significantly higher for the hCG group than for the spontaneous LH group. After adjustment for a number of confounding factors, the reproductive outcomes were still significantly worse for the spontaneous ovulatory group. Conclusions: Among women undergoing natural cycle IUI with donor sperm, hCG triggered ovulation for timing insemination offers beneficial impacts on both clinical pregnancy rates and live birth rates.

An experimental test of the ovulatory homolog model of female orgasm

The ovulatory homolog model of female orgasm posits that the neuro-endocrine mechanisms underlying female orgasm evolved from and are homologous to the mechanisms mediating copulation-induced ovulation in some mammals. This model predicts that pharmacological agents that affect human orgasm, such as fluoxetine, should also affect ovulation in animals with copulation-induced ovulation, such as rabbits. We tested this prediction by treating rabbits with daily doses of fluoxetine for 2 wk and found that fluoxetine treatment reduces the number of ovulations postcopulation by 30%. In a second experiment we tested whether this result was mediated by an effect on the brain or via peripheral serotonin functions. We treated animals with fluoxetine and induced ovulation with a single injection of human chorionic gonadotropin. In this experiment ovulation rate was nominally reduced by only 8%, which is statistically not significant. We conclude that the effect of fluoxetine on copulation-induced ovulation rate supports the ovulatory homolog model of female orgasm, suggesting that female orgasm has very deep evolutionary roots among the early eutherian mammals.

A borderline form of empty follicle syndrome treated with a double-trigger of gonadotropin-releasing hormone agonist and human chorionic gonadotropin: A case report

RATIONALE

The borderline form of empty follicle syndrome (EFS) is a phenomenon where only a few mature or immature oocytes are retrieved despite adequate response to controlled ovarian hyperstimulation (COH). It is a rare phenomenon with an unclear underlying mechanism, and there is currently no effective treatment.

PATIENT CONCERNS

The patient received 3 assisted reproductive technology cycles, and although her follicular development and estrogen levels were normal during COH, the outcome with respect to the oocytes obtained was unsatisfactory.

DIAGNOSES

Borderline form of EFS.

INTERVENTIONS

In the context of undergoing GnRH-antagonist protocol, we implemented a double-trigger with human chorionic gonadotropin (hCG) after 6 hours of gonadotropin-releasing hormone agonist (GnRH-a) administration.

OUTCOMES

Eleven oocytes were obtained (M I × 3, M II × 8), which underwent in vitro fertilization (IVF). After 18 hours, 7 oocytes showed normal fertilization, with 2 embryos formed 72 hours later (embryo rating, 6C II × 1, 9C II × 1); the embryos were then frozen.

LESSONS

Oocyte maturation and ovulation are time-dependent processes, and that different patients require different lengths/intervals of time for treatment. Therefore, the borderline form of EFS, in general, may be treatable, and our novel trigger method provides a new treatment option for such patients in the future.

ESR2 Is Essential for Gonadotropin-Induced Kiss1 Expression in Granulosa Cells

Hypothalamic expression of Kiss1 plays an essential role in the onset of puberty, gonadal development, and ovulation. Estrogens regulate the expression of Kiss1 in the hypothalamus through estrogen receptor-α. Kiss1 is also expressed in the ovary, where its expression correlates with the onset of puberty and progression of the estrous cycle. To date, estrogen regulation of Kiss1 expression in the ovary has not been investigated. We recently observed that gonadotropin-induced Kiss1 expression was absent in Esr2-null rat ovaries even though Esr1 was present. Wild-type granulosa cells abundantly expressed Kiss1 and oocytes expressed the Kiss1 receptor. We characterized estrogen receptor-β (ESR2) regulation of Kiss1 expression in granulosa cells by identifying granulosa cell-specific transcript variants and potential regulatory regions. The Kiss1 promoter, an upstream enhancer, and a downstream enhancer all possessed conserved estrogen response elements (EREs) and showed active histone marks in gonadotropin-stimulated granulosa cells. The transcriptionally active Kiss1 promoter, as well as the enhancers, also revealed enrichment for ESR2 binding. Furthermore, activity of a Kiss1 promoter construct was induced after overexpression of ESR2 and was blocked upon mutation of an ERE within the promoter. Finally, pregnant mare serum gonadotropin and human chorionic gonadotropin administration induced phosphorylation of ESR2 and upregulated the AP-1 proteins FOSL2 and JUNB in granulosa cells. Activated MAPK ERK2 was associated with the ESR2 phosphorylation in granulosa cells, and AP-1 factors could synergistically activate the Kiss1 promoter activity. These gonadotropin-induced changes paralleled Kiss1 expression in granulosa cells. We conclude that gonadotropin-stimulated Kiss1 expression in granulosa cells is dependent on both the activation of ESR2 and the upregulation of AP-1.

Core Binding Factor β Expression in Ovarian Granulosa Cells Is Essential for Female Fertility

Core binding factor β (CBFβ) is a non-DNA-binding partner of all RUNX proteins and critical for transcription activity of CBF transcription factors (RUNXs/CBFβ). In the ovary, the expression of Runx1 and Runx2 is highly induced by the luteinizing hormone (LH) surge in ovulatory follicles, whereas Cbfb is constitutively expressed. To investigate the physiological significance of CBFs in the ovary, the current study generated two different conditional mutant mouse models in which granulosa cell expression of Cbfb and Runx2 was reduced by Cre recombinase driven by an Esr2 promoter. Cbfbgc-/- and Cbfbgc-/- × Runx2gc+/- mice exhibited severe subfertility and infertility, respectively. In the ovaries of both mutant mice, follicles develop normally, but the majority of preovulatory follicles failed to ovulate either in response to human chorionic gonadotropin administration in pregnant mare serum gonadotropin-primed immature animals or after the LH surge at 5 months of age. Morphological and physiological changes in the corpus luteum of these mutant mice revealed the reduced size, progesterone production, and vascularization, as well as excessive lipid accumulation. In granulosa cells of periovulatory follicles and corpora lutea of these mice, the expression of Edn2, Ptgs1, Lhcgr, Sfrp4, Wnt4, Ccrl2, Lipg, Saa3, and Ptgfr was also drastically reduced. In conclusion, the current study provided in vivo evidence that CBFβ plays an essential role in female fertility by acting as a critical cofactor of CBF transcription factor complexes, which regulate the expression of specific key ovulatory and luteal genes, thus coordinating the ovulatory process and luteal development/function in mice.

The Cell Type-Specific Expression of Lhcgr in Mouse Ovarian Cells: Evidence for a DNA-Demethylation-Dependent Mechanism

The luteinizing hormone receptor (LHCGR) is expressed at low levels in mural granulosa cells and cumulus cells of antral follicles and is induced dramatically in granulosa cells but not in cumulus cells by follicle-stimulating hormone (FSH). Therefore, we hypothesized that FSH not only activates transcription factors controlling Lhcgr expression but also alters other events to permit and enhance Lhcgr expression in granulosa cells but not in cumulus cells. In granulosa cells, the level of DNA methylation in the Lhcgr promoter region was significantly decreased by equine chorionic gonadotropin (eCG) in vivo. However, in cumulus cells, hypermethylation of the Lhcgr promoter remained after eCG stimulation. eCG induced estrogen production from testosterone (T) and retinoic acid (RA) synthesis in granulosa cells. When either T or RA in the presence or absence of FSH was added to granulosa cell cultures, the combined treatment with FSH and RA induced demethylation of Lhcgr-promoter region and Lhcgr expression. FSH-dependent RA synthesis was negatively regulated by coculture of granulosa cells with denuded oocytes, suggesting that oocyte-secreted factors downregulate RA production in cumulus cells where Lhcgr expression was not induced. Strikingly, treatment of cultured cumulus-oocyte complexes with a SMAD inhibitor, SB431542, significantly induced RA production, demethylation of Lhcgr-promoter region, and Lhcgr expression in cumulus cells. These results indicate the demethylation of the Lhcgr-promoter region is mediated, at least in part, by RA synthesis and is a key mechanism regulating the cell type-specific differentiation during follicular development.

Dynamics of the development of multiple follicles by early versus late hCG administration in ART program

OBJECTIVE

To evaluate, in patients stimulated with recombinant FSH and GnRH antagonists, whether triggering the final maturation of oocytes affects IVF outcomes.

STUDY DESIGN

Five hundred and six IVF procedures were divided into three groups according to the timing of hCG administration: when at least 2 follicles reached the diameter of 17 mm, at least 2 follicles reached 18 mm and at least 2 follicles reached 20 mm. The main outcome was the number of mature oocyte that was the dependent variable of a multivariate model whose independents were, age, AFC, hCG timing, E2 levels at hCG day, number of follicles in different categories of dimension. Secondary endpoints were to compare fertilization, implantation and pregnancy rates in a multilevel multivariate model whose covariates were age, BMI, AFC, embryo quality and cause of infertility.

RESULTS

Timing did not result a statistically significant factor influencing the number of oocytes collected, which was influenced by age, AFC, number of follicles between 12.1 and 15.9 mm and E2 levels. Implantation rate and pregnancy rate appear to be affected only by embryo quality.

CONCLUSION

The number of oocytes collected and the probability of pregnancy are not associated with the time of hCG administration.

A study of intrauterine infusion of human chorionic gonadotropin (hCG) before frozen-thawed embryo transfer after two or more implantation failures

OBJECTIVE

To investigate the effect of intrauterine infusion of human chorionic gonadotropin (hCG) before frozen-thawed embryo transfer (FET) after two or more implantation failures (TIFs).

METHODS

The study was a prospective randomized single-blind study of 161 cycles in patients undergoing FET who had TIFs. The intervention group received an intrauterine injection of 1000 IU of hCG before embryo transfer (ET) (n = 62). A placebo group (n = 49) received an intrauterine injection of physiological saline before ET. A control group (n = 50) did not receive an intrauterine injection. Clinical pregnancy rates, abortion rates, and ongoing pregnancy rates were compared between the three groups.

RESULTS

The clinical pregnancy rates were 59.68%, 53.06%, and 32.00% in the hCG group, placebo group, and control group, respectively. The clinical pregnancy rates were significantly higher in the hCG and placebo groups than in the control group. There were no significant differences in the abortion rates among the three groups.

CONCLUSION

An intrauterine administration of hCG before FET significantly improved the pregnancy rates after TIFs. But local injury caused by the operation of intrauterine perfusion may play an important role in improving clinical pregnancy rates.

Metabolic changes in overweight and obese women above 35 years using Ethinylestradiol/drosperinone combined contraceptive pills: a 3-year case-control study

OBJECTIVE

To assess metabolic changes in overweight and obese women above 35 years using ethinylestradiol/drosperinone combined contraceptive pills for 36 cycles.

METHODS

A prospective case-control study over 3 years recruiting 202 overweight and obese women above the age of 35 years who were divided into two groups, study group (n = 90) who received Ethinylestradiol/drospirenone for 36 cycles, and control group (n = 112) to whom intrauterine device was inserted. Recording of the body weight, waist circumference, blood pressure, fasting blood glucose and fasting blood lipids including triglycerides, total cholesterol, low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol before starting the method and repeated at 12, 24 and 36 cycles of use.

RESULTS

No significant change was observed in body weight, waist circumference, blood pressure and fasting blood glucose between the two groups (p > 0.05).There was a significant reduction in triglycerides, total and LDL cholesterol with elevation in HDL cholesterol in the study group after 24 and 36 cycles of use (p < 0.05).

CONCLUSION

Ethinylestradiol/drospirenone combined contraceptive pills do not alter blood pressure or affect the body weight, with favorable effects on blood lipids in overweight and obese women above the age of 35 years when used for 24-36 cycles.

Expression, regulation, and function of drug transporters in cervicovaginal tissues of a mouse model used for microbicide testing

P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug resistance protein 4 (MRP4) are three efflux transporters that play key roles in the pharmacokinetics of antiretroviral drugs used in the pre-exposure prophylaxis of HIV sexual transmission. In this study, we investigated the expression, regulation, and function of these transporters in cervicovaginal tissues of a mouse model. Expression and regulation were examined using real-time RT-PCR and immunohistochemical staining, in the mouse tissues harvested at estrus and diestrus stages under natural cycling or after hormone synchronization. The three transporters were expressed at moderate to high levels compared to the liver. Transporter proteins were localized in various cell types in different tissue segments. Estrous cycle and exogenous hormone treatment affected transporter mRNA and protein expression, in a tissue- and transporter-dependent manner. Depo-Provera-synchronized mice were dosed vaginally or intraperitoneally with (3)H-TFV, with or without MK571 co-administration, to delineate the function of cervicovaginal Mrp4. Co-administration of MK571 significantly increased the concentration of vaginally-administered TFV in endocervix and vagina. MK571 increased the concentration of intraperitoneally-administered TFV in the cervicovaginal lavage and vagina by several fold. Overall, P-gp, Bcrp, and Mrp4 were positively expressed in mouse cervicovaginal tissues, and their expression can be regulated by the estrous cycle or by exogenous hormones. In this model, the Mrp4 transporter impacted TFV distribution in cervicovaginal tissues.

Intrauterine human chorionic gonadotropin infusion in oocyte donors promotes endometrial synchrony and induction of early decidual markers for stromal survival: a randomized clinical trial

STUDY QUESTION

Does a single intrauterine infusion of human chorionic gonadotropin (hCG) at the time corresponding to a Day 3 embryo transfer in oocyte donors induce favorable molecular changes in the endometrium for embryo implantation?

SUMMARY ANSWER

Intrauterine hCG was associated with endometrial synchronization between endometrial glands and stroma following ovarian stimulation and the induction of early decidual markers associated with stromal cell survival.

WHAT IS KNOWN ALREADY

The clinical potential for increasing IVF success rates using an intrauterine hCG infusion prior to embryo transfer remains unclear based on previously reported positive and non-significant findings. However, infusion of CG in the non-human primate increases the expression of pro-survival early decidual markers important for endometrial receptivity, including α-smooth muscle actin (α-SMA) and NOTCH1.

STUDY DESIGN, SIZE, DURATION

Oocyte donors (n=15) were randomly assigned to receive an intrauterine infusion of 500 IU hCG (n=7) or embryo culture media vehicle (n=8) 3 days following oocyte retrieval during their donor stimulation cycle. Endometrial biopsies were performed 2 days later, followed by either RNA isolation or tissue fixation in formalin and paraffin embedding.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Reverse transcription of total RNA from endometrial biopsies generated cDNA, which was used for analysis in the endometrial receptivity array (ERA; n = 5/group) or quantitative RT-PCR to determine relative expression of ESR1, PGR, C3 and NOTCH1. Tissue sections were stained with hematoxylin and eosin followed by blinded staging analysis for dating of endometrial glands and stroma. Immunostaining for ESR1, PGR, α-SMA, C3 and NOTCH1 was performed to determine their tissue localization.

MAIN RESULTS AND THE ROLE OF CHANCE

Intrauterine hCG infusion was associated with endometrial synchrony and reprograming of stromal development following ovarian stimulation. ESR1 and PGR were significantly elevated in the endometrium of hCG-treated patients, consistent with earlier staging. The ERA did not predict an overall positive impact of intrauterine hCG on endometrial receptivity. However, ACTA2, encoding α-SMA was significantly increased in response to intrauterine hCG. Similar to the hCG-treated non-human primate, sub-epithelial and peri-vascular α-SMA expression was induced in women following hCG infusion. Other known targets of hCG in the baboon were also found to be increased, including C3 and NOTCH1, which have known roles in endometrial receptivity.

LIMITATIONS, REASONS FOR CAUTION

This study differs from our previous work in the hCG-treated non-human primate along with clinical studies in infertile patients. Specifically, we performed a single intrauterine infusion in oocyte donors instead of either continuous hCG via an osmotic mini-pump in the baboon or infusion followed by blastocyst-derived hCG in infertile women undergoing embryo transfer. Therefore, the full impact of intrauterine hCG in promoting endometrial receptivity may not have been evident.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest a potential clinical benefit for intrauterine hCG prior to embryo transfer on Day 3 in counteracting endometrial dyssynchrony from ovarian stimulation and promoting expression of markers important for stromal survival. Finally, there were no obvious negative effects of intrauterine hCG treatment.

STUDY FUNDING/COMPETING INTERESTS

Funding for this work was provided by NICHD R01 HD042280 (A.T.F.) and NICHD F30 HD082951 (M.R.S.). C.S. and P.D.-G are co-inventors of the patented ERA, which is owned by IGENOMIX SL and was used in this study, and C.S. is a shareholder in IGENOMIX SL. M.R.-A. is employed by IGENOMIX SL. No other authors have any conflicts of interest to report.

TRIAL REGISTRATION NUMBER

This study was registered with ClinicalTrials.gov (NCT01786252).

TRIAL REGISTRATION DATE

5 February 2013.

DATE OF FIRST PATIENT'S ENROLLMENT

10 May 2013.

Revisiting the cost-effectiveness of universal cervical length screening: importance of progesterone efficacy

BACKGROUND

Preterm birth (PTB) is a significant cause of neonatal morbidity and mortality. Studies have shown that vaginal progesterone therapy for women diagnosed with shortened cervical length can reduce the risk of PTB. However, published cost-effectiveness analyses of vaginal progesterone for short cervix have not considered an appropriate range of clinically important parameters.

OBJECTIVE

To evaluate the cost-effectiveness of universal cervical length screening in women without a history of spontaneous PTB, assuming that all women with shortened cervical length receive progesterone to reduce the likelihood of PTB.

STUDY DESIGN

A decision analysis model was developed to compare universal screening and no-screening strategies. The primary outcome was the cost-effectiveness ratio of both the strategies, defined as the estimated patient cost per quality-adjusted life-year (QALY) realized by the children. One-way sensitivity analyses were performed by varying progesterone efficacy to prevent PTB. A probabilistic sensitivity analysis was performed to address uncertainties in model parameter estimates.

RESULTS

In our base-case analysis, assuming that progesterone reduces the likelihood of PTB by 11%, the incremental cost-effectiveness ratio for screening was $158,000/QALY. Sensitivity analyses show that these results are highly sensitive to the presumed efficacy of progesterone to prevent PTB. In a 1-way sensitivity analysis, screening results in cost-saving if progesterone can reduce PTB by 36%. Additionally, for screening to be cost-effective at WTP=$60,000 in three clinical scenarios, progesterone therapy has to reduce PTB by 60%, 34% and 93%. Screening is never cost-saving in the worst-case scenario or when serial ultrasounds are employed, but could be cost-saving with a two-day hospitalization only if progesterone were 64% effective.

CONCLUSION

Cervical length screening and treatment with progesterone is a not a dominant, cost-effective strategy unless progesterone is more effective than has been suggested by available data for US women. Until future trials demonstrate greater progesterone efficacy, and effectiveness studies confirm a benefit from screening and treatment, the cost-effectiveness of universal cervical length screening in the United States remains questionable.

Activin Decoy Receptor ActRIIB:Fc Lowers FSH and Therapeutically Restores Oocyte Yield, Prevents Oocyte Chromosome Misalignments and Spindle Aberrations, and Increases Fertility in Midlife Female SAMP8 Mice

Women of advanced maternal age (AMA) (age ≥ 35) have increased rates of infertility, miscarriages, and trisomic pregnancies. Collectively these conditions are called "egg infertility." A root cause of egg infertility is increased rates of oocyte aneuploidy with age. AMA women often have elevated endogenous FSH. Female senescence-accelerated mouse-prone-8 (SAMP8) has increased rates of oocyte spindle aberrations, diminished fertility, and rising endogenous FSH with age. We hypothesize that elevated FSH during the oocyte's FSH-responsive growth period is a cause of abnormalities in the meiotic spindle. We report that eggs from SAMP8 mice treated with equine chorionic gonadotropin (eCG) for the period of oocyte growth have increased chromosome and spindle misalignments. Activin is a molecule that raises FSH, and ActRIIB:Fc is an activin decoy receptor that binds and sequesters activin. We report that ActRIIB:Fc treatment of midlife SAMP8 mice for the duration of oocyte growth lowers FSH, prevents egg chromosome and spindle misalignments, and increases litter sizes. AMA patients can also have poor responsiveness to FSH stimulation. We report that although eCG lowers yields of viable oocytes, ActRIIB:Fc increases yields of viable oocytes. ActRIIB:Fc and eCG cotreatment markedly reduces yields of viable oocytes. These data are consistent with the hypothesis that elevated FSH contributes to egg aneuploidy, declining fertility, and poor ovarian response and that ActRIIB:Fc can prevent egg aneuploidy, increase fertility, and improve ovarian response. Future studies will continue to examine whether ActRIIB:Fc works via FSH and/or other pathways and whether ActRIIB:Fc can prevent aneuploidy, increase fertility, and improve stimulation responsiveness in AMA women.

D-Aspartic acid stimulates steroidogenesis through the delay of LH receptor internalization in a mammalian Leydig cell line

PURPOSE

Recent experimental evidence on non-mammalian animal models showed that D-Aspartic acid (d-Asp) administration increases testosterone levels through upregulation of StAR in Leydig cells. In this study, we aimed to investigate in vitro the signaling pathway associated with d-Asp stimulation in MA-10 murine Leydig cells.

METHODS

MA-10 cells were stimulated with different concentrations of d-Asp, in presence or absence of hCG. Then total testosterone (T) levels in the culture medium were evaluated by electrochemiluminescence immunoassay, and StAR and LHR protein expressions were quantified by the means of Western blotting. LHR cellular localization after hormonal stimulation was assessed by immunofluorescence.

RESULTS

Stimulation with the sole d-Asp did not induce any relevant increase of T release from cultured cells. On the other hand, stimulation with hCG induced significant increase of T (P = 0.045). Concomitant stimulation with hCG and d-Asp, at the concentration of 0.1 and 1 nM, induced additional and significant increase of released T (P = 0.03 and P = 0.04, respectively). StAR protein levels increased after concomitant stimulation with hCG and d-Asp 0.1 nM, compared with stimulation with the sole hCG (P = 0.02), whereas no variation in LHR protein expression was observed. Finally, d-Asp attenuated displacement of LHR staining, from cell membrane to cytoplasm, subsequent to hCG stimulation.

CONCLUSIONS

In this study, we confirmed a steroidogenic role for d-Asp, in concert with hCG, on murine Leydig cells, which is mediated by an increase in StAR protein levels. In addition, we showed that the possible mechanism subtending the effect of d-Asp could rely on the modulation of LHR exposure on the cell membrane.

Comparison of montelukast and cabergoline for prevention of ovarian hyperstimulation syndrome: in an experimental rat model

Ovarian hyperstimulation syndrome (OHSS) is a serious iatrogenic complication that can occur during assisted reproductive techniques. The aim of this study is to investigate the effects of the leukotriene receptor antagonist (montelukast) treatment in prevention of OHSS and compare to cabergoline treatment. Twenty-four immature female Wistar rats were assigned to four groups. Group 1 was the control group. In the remaining three groups, OHSS was induced through ovarian stimulation with gonadotropins. No treatment was given to Group 2. Group 3 was administered a low-dose 100 mg/kg cabergoline treatment and Group 4 was received 20 mg/kg montelukast. Body weight, ovarian weight, vasculary permability (VP), peritoneal fluid vascular endothelial growth factor (VEGF) values and VEGF immune-expression were compared between the groups. Both cabergoline and montelukast prevented progression of OHSS compared to the OHSS group. Body weight, ovarian weight, VP, peritoneal fluid VEGF values and VEGF expression were significantly lower in both cabergoline- and montelukast-treated rats than in those not treated OHSS group. In conclusion, montelukast is an effective option for prevention of OHSS, as well as cabergoline. Montelukast may be a new treatment option to prevent and control the OHSS.

Knockdown of CEBPβ by RNAi in porcine granulosa cells resulted in S phase cell cycle arrest and decreased progesterone and estradiol synthesis

Cultured ovarian granulosa cells (GCs) are essential models to study molecular mechanisms of gene regulation during folliculogenesis. CCAAT enhancer binding proteins β (CEBPβ) has been identified in the ovary and is critical for follicular growth, ovulation and luteinization in mice. In the present study, hormonal treatment indicated that luteinizing hormone (LH) and exogenous human chorionic gonadotropins (hCG) significantly increased the expression of CEBPβ in porcine GCs. By RNAi-Ready pSIREN-RetroQ-ZsGreen Vector mediated recombinant pshRNA vectors, CEBPβ gene was successfully knocked down in porcine GCs, confirmed by mRNA and protein level analyzed by real time PCR and western blot, respectively. We further found that knockdown of CEBPβ significantly increased the expression of p-ERK1/2. Furthermore, CEBPβ knockdown arrested the GCs at S phase of cell cycle, but had no effects on cell apoptosis. More importantly, it markedly down regulated the concentration of estradiol (E2) and progesterone (P4) in the culture medium. To uncover the regulatory mechanism of CEBPβ knockdown on cell cycle and steroids synthesis, we found that the mRNA expression of bcl-2 (anti-apoptosis), StAR and Runx2 (steroid hormone synthesis) was up-regulated, while genes related to apoptosis (Caspase-3 and p53), hormonal synthesis (CYP11A1) and cell cycle (cyclinA1, cyclinB1, cyclinD1) were down-regulated, suggesting that knockdown of CEBPβ may inhibit apoptosis, regulate cell cycle and hormone secretions at the transcriptional level in porcine GCs. Furthermore, knockdown of CEBPβ significantly increased the expression of PTGS2 and decreased the expression of IGFBP4, Has2 and PTGFR which are important for folliculogenesis in porcine GCs. In conclusion, this study reveals that CEBPβ is a key regulator of porcine GCs through modulation of cell cycle, apoptosis, steroid synthesis, and other regulators of folliculogenesis.

Effects of the estrous cycle and ovarian hormones on central expression of interleukin-1 evoked by stress in female rats

Exposure to stressors such as foot shock (FS) leads to increased expression of multiple inflammatory factors, including the proinflammatory cytokine interleukin-1 (IL-1) in the brain. Studies have indicated that there are sex differences in stress reactivity, suggesting that the fluctuations in gonadal steroid levels across the estrous cycle may play a regulatory role in the stress-induced cytokine expression. The present studies were designed to investigate the role of 17-β-estradiol (E2) and progesterone (Pg) in regulating the cytokine response within the paraventricular nucleus (PVN) of the hypothalamus through analysis of gene expression with real-time RT-PCR. Regularly cycling female rats showed a stress-induced increase in PVN IL-1 levels during the diestrous, proestrous, and estrous stages. During the metestrous stage, no change in IL-1 levels was seen following FS; however, estrogen receptor (ER)-β levels did increase. Ovariectomy resulted in an increase in PVN IL-1 levels, which was attenuated by treatment with estradiol benzoate (10 or 50 µg), indicating an E2-mediated anti-inflammatory effect. Ovariectomized rats treated with Pg (500 or 1,250 µg) showed no alteration in IL-1 levels, but Pg did up-regulate ER-β gene expression. The results from the current study implicate a potential mechanism through which high availability of endogenous Pg during the metestrous stage increases ER-β sensitivity, which in turn attenuates the PVN IL-1 response to stress. Thus, the interaction between gonadal steroid hormones and their central receptors may exert a powerful inhibitory effect on neuroimmune consequences of stress throughout the estrous cycle.

Activation of the GPR30 receptor promotes lordosis in female mice

BACKGROUND/AIMS

Estrogens are important effectors of reproduction and are critical for upregulating female reproductive behavior or lordosis in females. In addition to the importance of transcriptional regulation of genes by 17β-estradiol-bound estrogen receptors (ER), extranuclear signal transduction cascades such as protein kinase A (PKA) are also important in regulating female sexual receptivity. GPR30 (G-protein coupled receptor 30), also known as GPER1, a putative membrane ER (mER), is a G protein-coupled receptor that binds 17β-estradiol with an affinity that is similar to that possessed by the classical nuclear ER and activates both PKA and extracellular-regulated kinase signaling pathways. The high expression of GPR30 in the ventromedial hypothalamus, a region important for lordosis behavior as well as kinase cascades activated by this receptor, led us to hypothesize that GPR30 may regulate lordosis behavior in female rodents.

METHOD

In this study, we investigated the ability of G-1, a selective agonist of GPR30, to regulate lordosis in the female mouse by administering this agent prior to progesterone in an estradiol-progesterone priming paradigm prior to testing with stud males.

RESULTS

As expected, 17β-estradiol benzoate (EB), but not sesame oil, increased lordosis behavior in female mice. G-1 also increased lordosis behavior in female mice and decreased the number of rejective responses towards male mice, similar to the effect of EB. The selective GPR30 antagonist G-15 blocked these effects.

CONCLUSION

This study demonstrates that activation of the mER GPR30 stimulates social behavior in a rodent model in a manner similar to EB.

Ovarian regulation of neuromedin U and its local actions in the ovary, mediated through neuromedin U receptor 2

Neuromedin U (NMU) was originally identified as an anorexigenic peptide that modulates appetite as well as energy homeostasis through the brain-gut axis. Although growing evidence has linked NMU activity with the development of female reproductive organs, no direct expression of and function for NMU in these organs has been pinpointed. Using a superovulated rat model, we found that NMU is directly expressed in the ovary, where its transcript level is tightly regulated by gonadotropins. Ovarian microdissection and immunohistochemical staining showed clearly that NMU is expressed mainly in theca/interstitial cells and to a moderate extent in granulosa cells. Primary cell studies together with reporter assays indicated the Nmu mRNA level in these cells is strongly induced via cAMP signaling, whereas this increase in expression can be reversed by the degradation message residing within its 3'-untranslated region, which recruits cis-acting mRNA degradation mechanisms, such as the gonadotropin-induced zinc finger RNA-binding protein Zfp36l1. This study also demonstrated that NMUR2, but not NMUR1, is the dominant NMU receptor in the ovary, where its expression is restricted to theca/interstitial cells. Treatment with NMU led to induction of the early response c-Fos gene, phosphorylation of extracellular signal-regulated kinase 1/2, and promotion of progesterone production in both developing and mature theca/interstitial cells. Taken as a whole, this study demonstrates that NMU and NMU receptor 2 compose a novel autocrine system in theca/interstitial cells in which the intensity of signaling is tightly controlled by gonadotropins.

The role of IL-6 trans-signaling in vascular leakage: implications for ovarian hyperstimulation syndrome in a murine model

CONTEXT

The inflammatory cytokine IL-6 is related to ovarian hyperstimulation syndrome (OHSS), although the functional role of IL-6 in OHSS remains largely unknown.

OBJECTIVE

A key feature of the IL-6 response is that its regulation is dependent on IL-6 trans-signaling via soluble IL-6 receptor-α (sIL-6Rα). The objective of the study was to elucidate the mechanistic role of IL-6 trans-signaling in the vascular leakage that underlies the pathophysiology of OHSS.

DESIGN

Ovarian endothelial cells (ECs) and granulosa-lutein cells were obtained from women undergoing in vitro fertilization. OHSS was induced in mice by administering gonadotropins for 2 days followed by human chorionic gonadotropin. The functional role of IL-6 trans-signaling in OHSS was verified using the designer cytokines Hyper IL-6 and sgp130-Fc.

RESULTS

The follicular fluid levels of sIL-6Rα were elevated in women at high risk for OHSS. In the murine OHSS model, stimulation with gonadotropins significantly induces ovarian IL-6 and sIL-6Rα expression. In vitro, FSH induces de novo sIL-6Rα synthesis in granulosa-lutein cells through a protein kinase C-dependent pathway. In addition, sIL-6Rα was released by leukocytes in the presence of conditioned medium from human chorionic gonadotropin-treated granulosa-lutein cells. Ovarian ECs responded to the IL-6Rα-IL-6 complex (Hyper IL-6) but not to IL-6 alone. With activation of signal transducer and activator of transcription 3 (STAT3) and ERK, Hyper IL-6 increased vascular endothelial growth factor expression and the vascular permeability of ECs. Selective blockade of IL-6 trans-signaling by sgp130-Fc significantly inhibited vascular endothelial growth factor expression and prevented OHSS in mice.

CONCLUSIONS

IL-6 trans-signaling is activated during the ovarian stimulation process. Our findings provide insight into the biologic effects of IL-6 trans-signaling in OHSS and highlight that IL-6 trans-signaling can induce vascular leakage in this disease.

Expression and regulation of Ang-2 in murine ovaries during sexual maturation and development of corpus luteum

The aim of this study was to examine the expression and regulation of angiopoietin-2 (Ang-2) in murine ovaries during sexual maturation, gonadotropin treatment and luteal development by in situ hybridization and RT-PCR. By in situ hybridization Ang-2 mRNA was mainly localized in granulosa cells, thecal cells and corpus luteum, otherwise in oocytes. Moreover, Ang-2 mRNA was highly expressed in corpus luteum and granulosa cells of atretic follicles. According to RT-PCR data, Ang-2 mRNA was lowly expressed on day 10 after birth, then expression levels gradually increased and reached their highest values on day 25 after birth. In the superovulated model of immature mice, Ang-2 expression was strongly induced by equine chorionic gonadotropin (eCG) 48 h post the eCG injection, and was high from 0.5 to 13 h after hCG treatment. In situ hybridization showed that Ang-2 mRNA was highly expressed in corpus luteum from day 2 to 9 post the hCG injection, then the expression levels gradually declined on days 11 and 13 after hCG treatment. According to RT-PCR data, the levels of Ang-2 mRNA expression showed a decline after the hCG injection, with a nadir on day 3, followed by an increase, reaching the highest level on day 9 post-hCG injection. Then again Ang-2 expression gradually declined from day 11 to 15 after hCG injection. These results suggest that Ang-2 may be involved in follicular development, atresia, ovulation, and corpus luteum formation and regression.

Hormonal induction of polo-like kinases (Plks) and impact of Plk2 on cell cycle progression in the rat ovary

The highly conserved polo-like kinases (Plks) are potent regulators of multiple functions in the cell cycle before and during mitotic cell division. We investigated the expression pattern of Plk genes and their potential role(s) in the rat ovary during the periovulatory period. Plk2 and Plk3 were highly induced both in intact ovaries and granulosa cells in vivo after treatment with the luteinizing hormone (LH) agonist, human chorionic gonadotropin (hCG). In vitro, hCG stimulated the expression of Plk2 in granulosa cells, but not Plk3. This induction of Plk2 expression was mimicked by both forskolin and phorbol 12 myristate 13-acetate (PMA). Moreover, Plk2 expression was reduced by inhibitors of prostaglandin synthesis or the EGF pathway, but not by progesterone receptor antagonist (RU486) treatment. At the promoter level, mutation of the Sp1 binding sequence abolished the transcriptional activity of the Plk2 gene. ChIP assays also revealed the interaction of endogenous Sp1 protein in the Plk2 promoter region. Functionally, the over-expression of Plk2 and Plk3 arrested granulosa cells at the G0/G1 phase of the cell cycle. In contrast, the knockdown of Plk2 expression in granulosa cells decreased the number of cells in the G0/G1 stage of the cell cycle, but increased granulosa cell viability. In summary, hCG induced Plk2 and Plk3 expression in the rat ovary. Prostaglandins and the EGF signaling pathway are involved in regulating Plk2 expression. The transcription factor Sp1 is important for Plk2 transcriptional up-regulation. Our findings suggest that the increase in Plk2 and Plk3 expression contributes to the cell cycle arrest of granulosa cells which is important for the luteinization of granulosa cells during the periovulatory period.

Influence of progesterone on oocyte quality and embryo development in cows

In cattle, the majority of embryo loss occurs very early during pregnancy (approximately Day 16), around or prior to maternal recognition of pregnancy. The actions of P4 in controlling LH pulsatility and ovarian follicular development may impinge negatively on oocyte quality. A considerable proportion of embryo loss may be attributable to inadequate circulating progesterone (P4) concentrations and the subsequent downstream consequences on endometrial gene expression and histotroph secretion into the uterine lumen. Conceptus growth and development require the action of P4 on the uterus to regulate endometrial function, including conceptus-maternal interactions, pregnancy recognition, and uterine receptivity for implantation. This review summarizes recent data highlighting the role of progesterone in determining oocyte quality and embryo development in cattle.

Differential modulation of apoptotic gene expression by N-acetyl-L-cysteine in Leydig cells stimulated persistently with hCG in vivo

The present study was designed to investigate the molecular mechanisms of NAC (150 mg/kg bw twice/week) action in vivo under repeated hCG (100 IU/rat/day) stimulation to adult rats. Leydig cell refractoriness led to a significant decline in serum testosterone and intracellular cAMP by day 30 of chronic hCG intervention which improved significantly following NAC co-administration. It inhibited the rise in lipid peroxidation, improved the activity of antioxidant enzymes along with intracellular glutathione and total antioxidant capacity in the target cells. Leydig cell apoptosis declined significantly (P<0.001) with down-regulation of upstream, Fas, FasL, caspase-8, Bax and caspase-9, JNK/pJNK and downstream caspase-3 and PARP. On the other hand, anti-apoptotic Bcl2, NF-kβ, and Akt were up-regulated. Taken together, the above findings indicate that the specificity of NAC action was not restricted to regulating marker proteins in the extrinsic and JNK pathways as seen in vitro but extended to include intrinsic pathway of metazoan apoptosis as well.

Fixed-time deep uterine insemination in PGF2α-synchronized goats

The aim of this investigation was to optimize fixed-time insemination in goats by clustering ovulations in prostaglandin F(2α)-synchronized goats either with gonadotropin releasing hormone (GnRH) or human chorionic gonadotropin (hCG). The underlying intention was to reduce the incidence of short cycles by providing a more sustained stimulation of the corpus luteum by substituting the commonly used GnRH with longer-acting hCG. It was conjectured that this might render the corpus luteum less prone to premature regression. Sixty pluriparous does were administered 5 mg of the prostaglandin F(2α) preparation dinoprost (Dinolytic; Pharmacia and Upjohn, Erlangen, Germany) during the luteal phase of the estrous cycle. Twenty of these does were administered 0.004 mg of the GnRH analog buserelin (Receptal; Intervet, Unterschleissheim, Germany) 48 hours later; another 20 does received 500 IU hCG (Chorulon; Intervet, Unterschleissheim, Germany) instead. Sixteen hours later the does were inseminated with frozen-thawed semen. The remaining 20 does served as controls and were inseminated 16-18 h after the onset of detected estrus. All 60 treated goats displayed estrous symptoms, the time of onset being similar for all groups (42.6, 37.6, and 40.5 hours after treatment for GnRH-treated, hCG-treated, and control does, respectively). The duration of estrus in the GnRH-treated group was 10 h less than in the other groups (45.1 vs. 56.4 and 54.4 h, P < 0.05). The number of ovulations (assessed by ultrasound monitoring) did not differ among groups (2.4, 2.1, and 2.5, P > 0.05). Monitoring of serum progesterone revealed that the incidence of corpus luteum insufficiency was significantly higher in GnRH- and hCG-treated does than in the control group (40% and 35% vs. 5%, P < 0.05). The pregnancy rate was 50% in the GnRH and 35% in the hCG group as compared with 60% in the controls. Corresponding kidding rates were 40%, 35%, and 60% (P > 0.05). When disregarding does with corpus luteum insufficiency, pregnancy rates would have been 83%, 54%, and 63%, and kidding rates 67%, 54%, and 63%, respectively. The average number of kids born was 1.88, 1.71, and 1.83, respectively (P > 0.05). It may be concluded that fixed time insemination of cycling does treated with prostaglandin F(2α) during the luteal phase, followed by ovulation induction with GnRH or hCG, would be an effective management tool if it were possible to control the high incidence of corpus luteum insufficiency. The attempt to achieve this by substituting GnRH with hCG, was not met with success. Until a solution for the problem has been found, it is advisable to inseminate prostaglandin-synchronized does 16-18 hours after the onset of detected estrus.

Effect of contraceptives on aldosterone/renin ratio may vary according to the components of contraceptive, renin assay method, and possibly route of administration

BACKGROUND

The most popular screening test for primary aldosteronism is plasma aldosterone/renin ratio (ARR). Because both estrogen and progesterone affect aldosterone and renin levels, we studied effects of two contraceptives commonly used in our population, one oral and one subdermal, on ARR, measuring renin as both direct renin concentration (DRC) and plasma renin activity (PRA).

METHODS

Normotensive, healthy women underwent measurement (seated, midmorning) of plasma aldosterone, DRC, PRA, electrolytes, and creatinine and urinary aldosterone, cortisol, electrolytes, and creatinine at baseline (menses) and after either 1) 3 wk treatment with oral ethinylestradiol plus drospirenone (n = 17) or 2) 1 wk and 6 wk treatment with subdermal etonogestrel (n = 15), a third-generation progestin.

RESULTS

Treatment with oral ethinylestradiol plus drospirenone was associated with significant increases in aldosterone [median (range) at baseline = 131 (85-590) pmol/liter; at 1 wk, 200 (130-784) pmol/liter; and at 3 wk, 412 (199-1010) pmol/liter (P < 0.001, Friedman test)] and PRA [2.1 (1.2-4.7), 3.6 (1.5-7.1), and 4.9 (1.5-10.8) ng/ml · h, P < 0.001] but decreases in DRC [22 (11-36), 21 (8.7-41), and 14 (8.5-39) mU/liter, P < 0.01] leading to increases in ARR calculated by DRC [6.6 (3.3-31.3), 10.9 (5.2-58.9), and 29.8 (5.1-88.5), P < 0.001]. There were no significant changes in ARR calculated by PRA, plasma electrolytes and creatinine, and all urinary measurements. In contrast, treatment with subdermal etonogestrel was associated with no significant changes in PRA, DRC, aldosterone, or ARR at either 1 or 6 wk.

CONCLUSION

The combined oral contraceptive ethinylestradiol plus drospirenone is capable of significantly increasing ARR with risk of false-positive results during screening for primary aldosteronism, but only if DRC is used to calculate the ratio. Subdermal etonogestrel had no effect on ARR after 6 wk.

Preliminary results on the reproduction of a deep-sea snailfish Careproctus rhodomelas around the active hydrothermal vent on the Hatoma Knoll, Okinawa, Japan

Deep-sea snailfish Careproctus rhodomelas were collected from an active hydrothermal vent using a remotely operated vehicle (R.O.V. Hyper-dolphin) and a pressurized device (Deep-Aquarium). Careproctus rhodomelas exhibited a cystovarian-type ovary containing a small number of developing oocytes at different stages, suggesting that the fish is a batch-spawner that spawns large eggs (c. 6·0 mm) several times within its life span. In vitro culture of the oocytes in the presence of human chorionic gonadotropin showed that oestradiol-17β production fluctuated with oocyte development, suggesting that the oocytes were at the vitellogenic stage.

[Interstrain differences in testicular responses to hCG: effects of a female exposition]

It is known that among many animal species, including laboratory mice, a short-time exposition to a female causes activation of the pituitary-testicular axis in males, which then rapidly decreases. Effects of a prolonged female exposition on the testicular testosterone output in response to hCG injections were investigated in adult males of two inbred mice strains CBA/Lac and PT. The males of both genotypes kept with females for 5 days were injected subcutaneously with 10 IU of hCG 120 minutes before decapitation. Males of the same genotype and similar age keeping alone were served as control. The serum testosterone concentration and its testicular content were measured with immune-enzyme assay. It has been shown that the hCG increased the testosterone concentration and its testicular content in control males of both strains, but the testosterone output was expressed more significantly in PT males in comparison with CBA/Lac. The prolonged exposition of a female itself did not influence the testosterone output in males of both strains. However, it increased significantly the testicular response to hCG in PT strain. The data obtained suggest that a long-term exposition of a female could reinforce the testicular reactivity to hCG in genotype-dependent manner.

Inhibition of hCG-induced spawning by alpha-methylparatyrosine, a tyrosine hydroxylase inhibitor, in the catfish Heteropneustes fossilis (Bloch)

In this study, the effect of pharmacological inhibition of catecholaminergic activity on hCG-induced spawning was evaluated and correlated with tyrosine hydroxylase (TH) activity, the rate-limiting enzyme in catecholamine biosynthesis. Gravid female H. fossilis collected in both prespawning and spawning phases were given alpha-methylparatyrosine (alpha-MPT: 250 microg/g body weight, ip, an irreversible inhibitor of TH) and human chorionic gonadotropin (hCG: 100 IU/fish, ip) alone or in combination. The fish were sampled at different intervals for measuring hypothalamic and ovarian TH activity and checking spawning response. The administration of hCG resulted in ovulation and spawning in both phases with a higher response in the spawning phase. The administration of alpha-MPT did not induce any response, like the control fish. In the hCG + alpha-MPT groups, the spawning response of hCG was significantly inhibited and delayed by the inhibitor. The spawning response of hCG was accompanied by a significant increase in both hypothalamic and ovarian TH activity at 6 and 12 h of the injection. However, at 24hr the activity decreased except in the spawning phase. The alpha-MPT treatment inhibited TH activity significantly in a duration-dependent manner. In the hCG + alpha-MPT groups, enzyme activity was inhibited at all duration. The results indicate the involvement of catecholamines during the hCG-induced spawning and the specific functional nature of the involvement needs further investigation.

Regulation of ovarian steroidogenesis in vitro by IGF-I and insulin in common carp, Cyprinus carpio: stimulation of aromatase activity and P450arom gene expression

Regulation of ovarian steroidogenesis in vitro by recombinant human insulin-like growth factor-I (IGF-I) and bovine insulin (b-insulin) was investigated in intact follicles and isolated follicular cells of carp, Cyprinus carpio at vitellogenic stage of oocyte maturation. In intact follicles, IGF-I and b-insulin stimulated testosterone and 17beta-estradiol production in vitro. In isolated theca cells, IGF-I and b-insulin stimulated testosterone production, whereas in granulosa cells, they stimulated 17beta-estradiol production when testosterone was added in the incubation medium as precursor substrate. In intact follicles and in theca cells, IGF-I and b-insulin had no effect on HCG-stimulated testosterone production. HCG-stimulated 17beta-estradiol production, however, was significantly increased by IGF-I and b-insulin. To clarify the mechanism of 17beta-estradiol production by the ovarian follicles during vitellogenic stage of carp, effects of IGF-I and b-insulin either alone or in combination with HCG on aromatase activity (conversion of testosterone to 17beta-estradiol) and cytochrome P450 aromatase (P450arom) gene expression were investigated in vitro. IGF-I and b-insulin alone stimulated aromatase activity and P450arom gene expression and significantly enhanced HCG-induced enzyme activity and P450arom gene expression. Our results thus indicate that IGF-I and b-insulin alone can stimulate testosterone and 17beta-estradiol production in vitellogenic follicles of C. carpio by stimulating aromatase activity and P450arom gene expression. Evidence also provided for the modulation of HCG-induced aromatase activity and P450arom gene expression by IGF-I and b-insulin in such follicles.

[Testicular function in mice of inbred strains BALB/cLac, PT, and CBA/Lac]

The main features of male fertility: sperm production and abnormalities, testosterone serum concentration and its testicular content after hCG injections, weights of the testes and cauda epididymes, were studied in adult males of three inbred mice strains BALB/cLac, PT, and CBA/Lac. The CBA/Lac males were characterized by lower value of the epididymal sperm number, as well as lower weights of reproductive organs in comparison with males of other inbred strains. The lower number of sperm is accompanied in the CBA/Lac males with lower proportion of morphologically abnormal spermatozoa as compared to other strains that could compensate its decreased count and improve fertility. The baseline testosterone concentration and its testicular content did not differ among the three strains but the testosterone response to injection of 10 IU of hCG was weaker in the CBA/Lac males than in the others. The results indicate significant interstrain differences in testicular traits implicated in male fertility which may be correlated and compensate to each other.

Attenuation of cell cycle progression by 2,3,7,8-tetrachlorodibenzo-p-dioxin eliciting ovulatory blockade in gonadotropin-primed immature rats

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) reduces ovulation rate in rats. The present study was to investigate whether TCDD alters the progression of cell cycle, and thus resulting in the blockade of ovulation in gonadotropin-primed, immature rats. The ovulation rate and ovarian weight were reduced in intact rats given TCDD (32 µg/kg BW in corn oil) by gavage one day before pregnant mare's serum gonadotropin (PMSG; 5 IU/rat) injection. Flow cytometry demonstrated that the percentage of granulosa cells in S-phase was increased at 24 h following PMSG treatment, but declined at 8 h following hCG treatment in corn oil-treated rats. Interestingly, the number of S-phase cells in TCDD-treated rats was reduced 24 and 48 h following PMSG treatment. TCDD, however, increased the percentage of cells in G2/M-phase at 24 h following PMSG treatment. TCDD inhibited the mRNA levels of Cdk2 at 0 h and 24 h, and cyclin D2 at 24 h and 48 h following PMSG treatment. Protein levels of aryl hydrocarbon receptor in granulosa cells were elevated in TCDD-treated rats at 12 h and 24 h following PMSG treatment. The present study indicates that TCDD reduces S-phase cells and inhibits levels of Cdk2 and cyclin D2 at 24 h following PMSG treatment, implying the ovulation-inhibiting action of TCDD may be exerted through the attenuation of cell cycle progression via AhR-mediated cascade.

Human chorionic gonadotropin (hCG) prevents the transformed phenotypes induced by 17 beta-estradiol in human breast epithelial cells

Human chorionic gonadotropin (hCG), a hormone produced during pregnancy, can elicit life-long refractoriness to carcinogenesis by differentiation of the breast epithelium. Human breast epithelial cells MCF-10F form tubules in collagen, mimicking the normal ductules. We have shown that 17 beta-estradiol (E2) alter the ductulogenic pattern of these cells. The effect of the recombinant hCG (rhCG) in vitro was evaluated on the transformation of MCF-10F induced by E2. MCF-10F cells were treated with 70 nM E2 alone or in combination with 50 IU/ml rhCG during 2 weeks, while the controls were treated with DMSO (the solvent in which E2 was dissolved) or rhCG alone. At the end of treatment, the cells were plated in type I collagen matrix (3D-cultures) for detecting 2 main phenotypes of cell transformation, namely the loss of ductulogenic capacity and the formation of solid masses. Although E2 significantly increased solid mass formation, this effect was prevented when MCF-10F cells were treated with E2 in combination with rhCG. Furthermore, E2 increased the main duct width (p < 0.001), and caused a disruption of the luminal architecture, whereas rhCG increased the length of the tubules (p < 0.001) and produced tertiary branching. In conclusion, rhCG was able to abrogate the transforming abilities of estradiol, and had the differentiating property by increasing the branching of the tubules formed by breast epithelial cells in collagen. These results further support our hypothesis, known as the terminal differentiation hypothesis of breast cancer prevention, that predicts that hCG treatment results in protection from tumorigenic changes by the loss of susceptible stem cells 1 through a differentiation to refractory stem cells 2 and increase differentiation of the mammary gland.

Regulation and function of tissue inhibitor of metalloproteinase (TIMP) 1 and TIMP3 in periovulatory rat granulosa cells

In the ovary, the matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinase (TIMPs) have been postulated to regulate extracellular matrix remodeling associated with ovulation. In the present study, we investigated the regulatory mechanisms controlling expression of Timp1 and Timp3 mRNA in periovulatory granulosa cells. Granulosa cells were isolated from immature pregnant mare serum gonadotropin-primed (10 IU) rat ovaries and treated with human chorionic gonadotropin (hCG; 1 IU/ml). At 4 h after hCG treatment, Timp1 expression was highest and then decreased gradually over the remaining 24 h of culture. In contrast, hCG induced a biphasic increase of Timp3 expression at 2 and 16 h. The hCG stimulated expression of Timp1 and Timp3 mRNA was blocked by inhibitors of the protein kinase A (H89), protein kinase C (GF109203), and MAPK (SB2035850) pathways. To further explore Timp1 and Timp3 regulation, cells were cultured with the progesterone receptor antagonist RU486, which blocked the hCG induction of Timp3 expression, whereas the epidermal growth factor receptor tyrosine kinase inhibitor AG1478 blocked the hCG stimulation of both Timp1 and Timp3 expression. The prostaglandin-endoperoxide synthase 2 inhibitor NS-398 had no effect. The potential function of TIMP3 was investigated with Timp3-specific small interfering RNA treatment. Timp3 small interfering RNA resulted in a 20% decrease in hCG-induced progesterone levels and microarray analysis revealed an increase in cytochrome P450 Cyp 17, ubiquitin conjugating enzyme E2T, and heat shock protein 70. IGF binding protein 5, stearyl-CoA desaturase, and annexin A1 were decreased. The differential regulation between Timp1 and Timp3 may correlate with their unique roles in the processes of ovulation and luteinization. For TIMP3, this may include regulating fatty acid synthesis, steroidogenesis, and protein turnover.

Activation of the lutropin/choriogonadotropin receptor inhibits apoptosis of immature Leydig cells in primary culture

We used proliferating primary cultures of immature rat Leydig cells expressing the recombinant human LH/choriogonadotropin (CG) receptor (LHR) to test the hypothesis that activation of this receptor inhibits apoptosis. We also compared the effects of LH/CG with epidermal growth factor (EGF) and IGF-I because these have been previously shown to stimulate proliferation and/or inhibit apoptosis in Leydig cells. Human CG (hCG), EGF, and IGF-I stimulated the phosphorylation of ERK1/2 and Akt in primary cultures of immature rat Leydig cells. These three hormones also robustly stimulated thymidine incorporation and inhibited drug-induced apoptosis. Using selective inhibitors of ERK1/2 (UO126) or Akt phosphorylation (LY294002), we show that the ERK1/2 and Akt cascades are both involved in the hCG- and EGF-dependent proliferation of Leydig cells, but only the ERK1/2 cascade is involved in their antiapoptotic actions. The same strategy showed that the proliferative and antiapoptotic actions of IGF-I are mediated entirely by the Akt pathway. These results show that activation of the LHR inhibits apoptosis in Leydig cells and that it does so through stimulation of the ERK1/2 pathway.

Expression of ectodermal neural cortex 1 and its association with actin during the ovulatory process in the rat

Ectodermal neural cortex (ENC) 1, a member of the kelch family of genes, is an actin-binding protein and plays a pivotal role in neuronal and adipocyte differentiation. The present study was designed to examine the gonadotropin regulation and action of ENC1 during the ovulatory process in immature rats. The levels of ENC1 mRNA and protein were stimulated by LH/human chorionic gonadotropin (hCG) within 3 h both in vivo and in vitro. In situ hybridization analysis revealed that ENC1 mRNA was localized not only in theca/interstitial cells but also in granulosa cells of preovulatory follicles but not of growing follicles in pregnant mare's serum gonadotropin/hCG-treated ovaries. LH-induced ENC1 expression was suppressed by a high dose of protein kinase C inhibitor RO 31-8220 (10 microM) but not by low doses of RO 31-8220 (0.1-1.0 microM), suggesting the involvement of atypical protein kinase C. ENC1 was detected in both nucleus and cytoplasm that was increased by LH/hCG treatment. Both biochemical and morphological analysis revealed that LH/hCG treatment increased actin polymerization within 3 h in granulosa cells. Interestingly, ENC1 physically associated with actin and treatment with cytochalasin D, an actin-depolymerizing agent, abolished this association. Confocal microscopy further demonstrated the colocalization of ENC1 with filamentous actin (F-actin). The present study demonstrates that LH/hCG stimulates ENC1 expression and increases F-actin formation in granulosa cells. The present study further shows the physical association of ENC1 and F-actin, implicating the role of ENC1 in cytoskeletal reorganization during the differentiation of granulosa cells.

Determination of hormones inducing oocyte maturation in Chalcalburnus tarichi (Pallas, 1811)

Chalcalburnus tarichi is an endemic cyprinid species living in the Lake Van basin, in eastern Anatolia, Turkey. The present study was undertaken to determine which hormones induce oocyte maturation in C. tarichi. The levels of 17alpha,20beta,21-trihydroxyprogesterone (20beta-S), progesterone (P), 17alpha-hydroxyprogesterone (17alpha-HOP), 11-deoxycortisol (11-DOC), and 17alpha-hydroxy-20beta-dihydroprogesterone (17,20beta-P) were measured in fish caught from Lake Van and the Karasu River, and injected with human chorionic hormone (hCG) (1,000 and 1,500 IU/kg). Oocytes of fish caught from the lake were also incubated in vitro with different doses (50, 200, and 1,000 ng/ml) of 20beta-S, 17alpha-HOP, 11-DOC, and 17,20beta-P. 11-DOC was found to be the most effective hormone among those measured for inducing oocyte maturation in vivo and in vitro. 17,20beta-P could not be determined in the plasma of any fish in vivo (P < 0.05). 1,000 IU/kg dose of hCG given by injection caused a statistically significant increase in all plasma hormone levels (P < 0.05). It was found that there was a significant decrease in the P level only at 1,500 IU/kg dose of hCG injected (P < 0.05), while the level of other hormones increased at this dose (P < 0.05). It was also determined that all the hormones were effective in germinal vesicle breakdown (GVBD) in in vitro oocyte culture (P < 0.05). However, 11-DOC was found to be the most effective hormone in GVBD at a dose of 200 ng/ml (70% GVBD). In conclusion, 11-DOC synthesized during final oocyte maturation in C. tarichi was found to be a potent inducer of GVBD, which shows that 11-DOC may be described as an oocyte maturation steroid in this species.

Human chorionic gonadotropin stimulates trophoblast invasion through extracellularly regulated kinase and AKT signaling

Chorionic gonadotropin (CG) is indispensable for human pregnancy because it controls implantation, decidualization, and placental development. However, its particular role in the differentiation process of invasive trophoblasts has not been fully unraveled. Here we demonstrate that the hormone promotes trophoblast invasion and migration in different trophoblast model systems. RT-PCR and Western blot analyses revealed expression of the LH/CG receptor in trophoblast cell lines and different trophoblast primary cultures. In vitro, CG increased migration and invasion of trophoblastic SGHPL-5 cells through uncoated and Matrigel-coated transwells, respectively. The hormone also increased migration of first-trimester villous explant cultures on collagen I. Proliferation of the trophoblast cell line and villous explant cultures measured by cumulative cell numbers and in situ 5-bromo-2'-deoxyuridine labeling, respectively, was unaffected by CG. Addition of the hormone activated ERK-1/2 and AKT in SGHPL-5 cells and pure, extravillous trophoblasts. Inhibition of MAPK kinase/ERK and phosphatidylinositide 3-kinase/AKT blocked phosphorylation of the kinases and attenuated CG-dependent invasion of SGHPL-5 cells. Similarly, the inhibitors decreased hormone-stimulated migration in villous explant cultures. Western blot analyses and gelatin zymography suggested that CG increased matrix metalloproteinase (MMP)-2 protein levels and activity in both culture systems. Inhibition of ERK or AKT diminished CG-induced MMP-2 expression. In summary, the data demonstrate that CG promotes trophoblast invasion and migration through activation of ERK and AKT signaling involving their downstream effector MMP-2. Because the increase of CG during the first trimester of pregnancy correlates with rising trophoblast motility, the hormone could be a critical regulator of the early invasion process.

An update of luteal phase support in stimulated IVF cycles

Stimulated IVF cycles are associated with luteal phase defect. In order to overcome this, different doses, durations and types of luteal phase support (LPS) have been evaluated. There is still no agreement regarding the optimal supplementation scheme. The aim of this paper is to assess the past and the current clinical practices of luteal supplementation in IVF. The databases of Medline and PubMed were searched to identify relevant publications. LPS with human chorionic gonadotrophin (hCG) [n=262, odds ratio (OR) 2.72 (95%), confidence interval (CI) 1.56-4.90, P<0.05] or progesterone (n=260, OR 1.57 CI 1.13, 2.17, P<0.05) results in an increased pregnancy rate compared with placebo, however, hCG is associated with increased risk of ovarian hyperstimulation syndrome. Natural micronized progesterone is not efficient if taken orally. The data on oral dydrogesterone are still conflicting. Vaginal and intra muscular progesterone have comparable outcomes. The addition of estradiol (E2) seems to be beneficial in long GnRH agonist protocol (implantation rate 39.6% with E2 compared with no E2; P<0.05) but not in the short GnRH agonist and GnRH antagonist protocol. Despite the early promising results, it is too early to recommend the use of GnRH agonist in LPS. LPS should cease on the day of positive HCG. Since the cause of luteal phase defect in IVF appears to be related to the supraphysiological levels of steroids, milder stimulation protocols should be advocated in order to eventually overcome the luteal phase defect.

Interventions After Artificial Insemination: Conception Rates, Pregnancy Survival, and Ovarian Responses to Gonadotropin-Releasing Hormone, Human Chorionic Gonadotropin, and Progesterone

We hypothesized that increasing concentrations of progesterone (P4) after artificial insemination would increase fertility. Our objective was to assess changes in ovarian structures, incidence of ovulation, and change in serum P4 in response to GnRH, human chorionic gonadotropin (hCG), or exogenous P4 (controlled internal drug release; CIDR insert) treatment beginning 4 to 9 d after artificial insemination (d 0) and again 7 d later (experiment 1). Blood was collected from 753 cows in 3 herds on d 0 and 7. Ovaries of 162 cows were scanned and mapped to confirm the presence of a corpus luteum (CL), and cows were assigned randomly to serve as controls (n = 41) or to receive a CIDR insert for 7 d (n = 41), 100 microg of GnRH (n = 40), or 3,300 IU of hCG (n = 40). More cows were induced to ovulate in response to GnRH (60%) and hCG (78%) compared with controls (2.4%). Compared with controls, cows treated with GnRH or hCG had more induced CL (d 7) and more total CL (d 7), but serum P4 was increased only in response to hCG. Largest follicle diameters on d 7 were less after GnRH and hCG, but total follicular volume on d 7 was reduced by GnRH, hCG, and CIDR, compared with that of controls. Volume of the original luteal structures was increased by hCG but tended to be reduced by CIDR and GnRH compared with luteal volume in controls. Total CL volume was increased by hCG, but reduced by CIDR, compared with CL volume of controls. Conception rates and pregnancy survival were assessed in response to the same treatments described in experiment 1: controls (n = 708), CIDR (n = 711), GnRH (n = 719), and hCG (n = 714). Tendencies for interactions of treatment x herd and treatment x lactation group were detected, but no 3-way interactions were found. Treatment with hCG increased conception rates in second-lactation cows. The CIDR tended to increase, and hCG increased, conception rates in 2 herds, whereas the CIDR decreased conception rates in 1 herd. Pregnancy survival was reduced by GnRH compared with that in controls. We concluded that GnRH and hCG effectively induced ovulation, and increased number of CL, but only increased serum P4 in hCG-treated cows. Further, treatment with the CIDR or hCG increased conception rates but only in some herds.

Vascular endothelial growth factor response to exogenous chorionic gonadotropic hormone in the luteal phase of women with a history of severe ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) is a severe complication of ovarian stimulation. No reliable test exists to predict the syndrome. The objective of the present prospective observational study was to examine vascular endothelial growth factor (VEGF) secretion after human chorionic gonadotropin (hCG) administration in the luteal phase of a spontaneous cycle of women with a history of severe OHSS. Five women with a history of severe OHSS were administered 250 mug recombinant hCG intravenously on day 21 of a spontaneous menstrual cycle. Plasma samples were collected at regular intervals from 15 min before hCG to 6 h thereafter and the free VEGF plasma concentrations were determined. Plasma levels of free VEGF remained at the lower detection limit of the assay throughout the observational period. Women with previous severe OHSS do not show a significant short-time response of VEGF secretion upon hCG administration. No evidence was found to support the notion that women inclined to develop a severe form of the syndrome after ovarian stimulation could possibly be identified by the VEGF short-time secretory response to exogenous hCG in the luteal phase of a spontaneous cycle.

[Advances in study on bark of Albizzia julibrissin]

Cortex Albizziae, the stem bark of the leguminous plant Albizzia julibrissin, is specified in Chinese pharmacopoeia as a traditional Chinese medicine used to relieve melancholia and uneasiness of body and mind, invigorate the circulation of blood and subside a swelling. This article reviews the recent advances in chemical constituents and pharmacological activities of Cortex Albizziae.

Quinacrine sterilization (QS) in Iran and the use of HSG as a measure of success

OBJECTIVES

To establish the safety, effectiveness and acceptability of quinacrine sterilization (QS) in Iran. To determine whether the hysterosalpingogram (HSG) performed under low pressure can be used to demonstrate success of the QS procedure rather than waiting for a pregnancy to occur in order to demonstrate failure.

METHODS

This study was initiated in September 1990 in a private family planning clinic in Tehran, Iran. Patient intake for this analysis was completed 31 December 1998 and the cut-off date for follow-up data to be included in this analysis was 30 July 2002. During this period, 268 women received QS. From inception until April 1994, 160 women entered the study. The first 62 women received 3 insertions and the remainder received 2. Short-term side effects were closely followed in these 160 women. From 18 February 1994 until the patient intake cut-off date, 131 women entered the study and 46 of them received an HSG.

RESULTS

With 4 to 12 years of follow-up there have been 7 pregnancies for a gross pregnancy rate of 2.6%. However, the use of the HSG tripled the risk of pregnancy for women who underwent the procedure. Furthermore, HSG, even when performed under minimal pressure, indicated failure of the QS procedure about 6% of the time when in fact both tubes would have closed had there been no intervention. Side effects were minor when compared to the complications of surgical sterilization.

CONCLUSIONS

QS was found to be safe, effective and preferred over surgical sterilization by Iranian women. HSG understated the number of patients with bilateral tubal closure, or with tubes that would have closed given a little more time.

Isocupressic acid blocks progesterone production from bovine luteal cells

The needles of ponderosa pine (Pinus ponderosa Laws.) were reported to induce abortions when fed to late-term pregnant beef cows in North America. An in vivo study of pregnant cows suggested that isocupressic acid (IA) was the main abortifacient isolated from needles and bark of the pine. However, the mechanism of abortifacient activity of IA is not clear yet. In a pregnant cow, the corpus luteum of the ovary helps the maintenance of pregnancy by its progesterone production. This study involved the IA extracted from the root of the Taiwan cypress (Juniperus formosana) and used a frozen-thawed bovine luteal cell culture system to investigate the action of IA on progesterone production. Thawed bovine luteal cells (1 x 10(5) cells/ml/well) in M199 medium were cultured in 24-well culture plates at 37 degrees C in a 5% CO2 incubator. Ten ml of tested drugs, IA at 1 to 1000 ng/ml and/or ovine luteinizing hormone (oLH) at 1 to 100 ng/microl or 8-bromo-cyclic adenosine monophosphate (8-Br-cAMP) with 0.1-10 mM, were added into each well. After 4 hours of incubation, the media were harvested and assayed for progesterone by an enzyme immunoassay. Progesterone production from cells was the indicator used to evaluate the action of IA. All tested doses of IA significantly inhibited progesterone production in both basal and oLH stimulating conditions. Also those dosages inhibited cyclic adenosine-3',5'- monophosphate (cAMP) stimulation, suggesting a post-cAMP mechanism is involved in the IA action. We concluded that IA can induce pregnant cows to abort partly through blocking luteal function and may be identified as a new abortifacient chemical.